Textile & Fashion World

These mechanisms are next in importance to the primary mechanisms. If weaving is to be continuous, these mechanisms are essential. So they are called the ‘secondary’ mechanisms. They are:

Take-up motion
The take-up motion withdraws the cloth from the weaving area at a constant rate so as to give the required pick-spacing (in picks/inch or picks/cm) and then winds it on to a cloth roller.

The main part of the mechanism is the take up rollers, which draws the cloth at the regular rate, and the number of picks per inch decides this rate. The take up roller is covered with emery cloth or hard rubber depending upon the type of cloth woven. The drive to the take up roller is by a train of gear wheels put into motion directly from the main shaft.

Let-off motion
The let-off motion delivers the warp to the weaving area at the required rate and at constant tension by unwinding it from the weaver’s beam. The secondary motions are carried out simultaneously. The speed of the servo motor is transmitted to warp beam gear via reduction gear, thus driving beam.

http://textilelearner.blogspot.com/2011/06/take-up-motion-let-off-motion-secondary_5888.html#ixzz2OCgjF200